1. Field of Invention
The present invention relates generally to a three wheel cambering vehicle and more specifically it relates to a cambering vehicle with a rocking-bar cambering mechanism and trailing arm folding mechanism, for providing better maneuverability and stability during cambering maneuver, and for easier operation of folding. better maneuverability and stability are achieved through an original cambering mechanism with a rocking-bar connecting spherical bearings and polymer energy-storing element. The easier operation of folding is achieved through an original, easy to operate and anti-disengagement sleeve-type folding mechanism. The invention also uses a one-piece steering handlebar and a quick handlebar locking mechanism to improve the robustness of the steering, and easiness of assembly.
2. Description of the Related Art
It can be appreciated that three wheel cambering vehicles have been in use for years. Typically, three wheel cambering vehicles are comprised of a steerable front wheel controlled by a steering handlebar (just as for a regular bicycle); a pair of rear wheels on mounted on the two trailing arms; two foot pedals on the trailing arms; two brakes on the rear wheels; a trailing arm folding and locking mechanism to make the vehicle portable; and a cambering mechanism which interconnects the steering column and two trailing arms.
The main problems of conventional three wheel cambering vehicles are commonly with the cambering mechanism. The cambering mechanism for the vehicles patented in U.S. Pat. Nos. 6,220,612 & 6,499,751 (Cambering vehicle and mechanism), U.S. Pat. No. 6,467,781 (Tricycle), U.S. Pat. No. 6,517,093 (Foldable tricycle), and U.S. Pat. No. 6,554,302 (Tricycle operated by torsion thereof) are based on the same principle. It has a freely rotating yoke in the middle, whose ends are connected with the polymer donuts on the two trailing arms. With this design, when the vehicle tilts, the yoke deforms the polymer donuts. The two polymer donuts serve both as the connection elements and as the energy storing element (spring). When the rider of the vehicle tilts his or her body to the inside of the turn to perform cambering maneuver, the polymer donut on the trailing arm at the inner side of the turn is deformed easily by the body weight. But, the deformation of the donut on the trailing arm at the opposite side relies on the push of the foot. If the foot fails to push enough to deform the polymer donut, the wheel at the outer side of the turn has the tendency to lift off the ground. It is especially so for deeply tilted turns. The lift of the wheel makes the motion unstable and may cause the maneuver to be out of control. The root cause of the situation is two independent energy-storing element. Actually, this double polymer-donut design also makes tilting rigid, especially for children or for sharp turn maneuvers.
The second common problem with conventional three wheel cambering vehicles is that their folding mechanisms aren't easy to use, since they all use finger pressure. Pins are always jammed due to the nature of the folding mechanism. It's difficult to apply adequate finger pressure, especially for children.
Another problem with conventional three wheel cambering vehicles is that they either have a two-piece steering handlebar design, which is not robust, or they have a one-piece handlebar design but the assembly and disassembly are not convenient. This convenience is important since the portability of the vehicle relies on it.
While these devices may be suitable for the particular purpose to which they are intended, there are limits and inconveniences as described above. It is highly beneficial to improve the design to achieve better maneuverability and stability during cambering maneuver, easier operation of folding, and robustness of a one-piece quick assembly and disassembly handlebar. In these respects, the cambering vehicle with rocking-bar cambering mechanism according to the present invention substantially departs from the conventional concepts and designs of the prior art. In so doing, the present invention provides an apparatus primarily developed for the purpose of providing better maneuverability and stability during cambering maneuver, easier operation of folding, and robustness of a one-piece quick assembly and disassembly handlebar. The invention presented here achieves these through an original cambering mechanism with a rocking-bar connecting spherical bearings and a polymer energy-storing element, an original, easy to operate and anti-disengagement sleeve-type folding mechanism, and a one-piece steering handlebar with a quick handlebar locking mechanism.